LOW-ENERGY CONSTRAINTS ON NEW PHYSICS REEXAMINED

It is possible to place constraints on non-standard-model gauge-boson self-couplings and other new physics by studying their one-loop contri butions to precisely measured observables. We extend previous analyses which constrain such nonstandard couplings, and we present the result s in a compact and transparent form. Particular attention is given to comparing results for the light-Higgs scenario, where nonstandard effe cts are parametrized by an effective Lagrangian with a linear realizat ion of the electroweak symmetry-breaking sector, and the heavy-Higgs o r strongly interacting scenario, described by the electroweak chiral L agrangian. The constraints on nonstandard gauge-boson self-couplings w hich are obtained from a global analysis of low-energy data and CERN L EP or SLC measurements on the Z pole are updated and improved from pre vious studies.